Rx_2.6 (Renal) Flashcards Preview

USMLE Step 1 > Rx_2.6 (Renal) > Flashcards

Flashcards in Rx_2.6 (Renal) Deck (18)
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1

Oliguria + elevated BUN/Cr following tx for leukemia ==> dx?

  • acute renal failure due to Tumor Lysis Syndrome
    • cytotoxic chemotherapy ==> destruction of neoplastic cells ==> dump cellular contents
    • ==> hyperphosphatemia + elevated purines + hypocalcemia
    • metabolic acidosis
    • purines metabolized to uric acid + other metabolites ==> overwhelm kidney ==> acute renal failure

2

Prevention of Tumor Lysis Syndrome

  • Allopurinol = xanthine oxidase (final step in synthesis of uric acid from purines) inhibitor
    • typically used in tx of gout

3

Presentation of tubulointerstitial nephritis

  • low-grade fever
  • rash
  • arthralgias
  • sx/signs of acute renail failure
  • UA
    • sterile pyuria (WBCs w/out bacteria)
    • microscopic hematuria
    • eosinophiluria

4

Drugs associated w/tubulointerstitial nephritis

  • most commonly associated with drugs
  • sulfonamides 
    • thiazide diuretics
    • loop diuretics
  • antibiotics
    • methicillin
    • ciprofloxacin
    • cephalosporins
    • rifampin
  • allopurinol
  • proton pump inhibitors
  • cimetidine
  • NSAIDs

5

Cyclophosphamide: MOA, SE

  • MOA: alkylating agent; cross-links DNA and prevents DNA synthesis and cell division
    • anti-neoplastic agent
    • immunosuppressant
  • SE:
    • alopecia
    • myelosuppression
    • N/V
    • hemorrhagic cystitis
    • renal tubular necrosis
      • ==> muddy, brown casts in UA

6

Diphenhydramine: MOA, use, SE

  • MOA: first-gen H1-antagonist
  • Uses
    • allergic rxns
    • motion sickness
    • dystonic rxns
  • SE
    • sedation
    • anticholinergic effects
    • anti-alpha-adrenergic effects

7

Isoniazid: MOA, use, SE

  • MOA: decreased synthesis of mycolic acids
  • Use: TB tx
  • SE
    • neurotoxicity
    • hepatotoxicity
    • lupus-like syndrome
    • hemolysis @ G-6-P deficient patients

8

Lithium: SE

  • CNS depression
  • dizziness
  • nephrogenic diabetes insipidus
  • acne
  • edema
  • hyperthyroidism
  • associated w/chronic tubulointerstitial nephritis ==> presents years after lithium therapy

9

Tx of post-infectious glomerulonephritis @ children

supportive care

10

Presentation and tx of minimal change disease

  • Presentation
    • Recent URI
    • periorbital swelling, generalized edema
    • malaise
  • Tx
    • first line = corticosteroid
    • second line =
      • chlorambucil: interferes w/DNA replication and RNA trxn
      • cyclosporine = inhibits IL-2 ==> suppression of T-cell activation

11

Presentation of renal artery stenosis

  • elevated BP, edema
  • renal artery bruits

12

Contraindicated drug in bilateral renal artery stenosis

  • ACE-inhibitor
  • ACE-i prevent the contriction of the efferent arteriole, which is the compensation mechanism of the kidneys to increase GFR
  • ACE-i ==> dilation of efferent arteriole ==> decreased GFR ==> increased creatinine

13

Common adverse effects of ACE-i

  • dry cough
  • hyperkalemia

14

Berger's disease characteristics 

  • "IgA nephropathy"
  • IgA deposits @ mesangium ==> nephritic syndrome
  • commonly exacerbated after URI

15

p-anca + eosinophilia ==> dx?

  • Churg-strauss syndrome
  • granulomatous small- to medium-sized vessel vasculitis
  • sx/signs
    • eosinophilia
    • necrotizing nephritis (w/out immune complexes or antibody deposition)
    • asthma
    • elevated P-ANCA

16

Characteristics of membranoproliferative glomerulonephritis

  • most common @ children, young adults
  • histologic findings
    • mesangial expansion + endothelial cell proliferation ==>
    • "tram track" appearance on EM
    • immune complex deposition present

17

Kidney response to decreased perfusion pressure

  • kidney maintains GFR via dilation of afferent arteriole and constriction of efferent arteriole
  • local afferent vasodilation via increased PG production by baroreceptors @ afferent arteriole
  • JGA cells release renin ==> ACE ==> angiotensin I --> angiotensin II ==>
  • aldosterone release/salt resorptioon + vasoconstriction

18

Cause of secondary parathyroid hormone production

  • often due to reduction in phosphate excretion
    • occurs in chronic renal failure

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